Published: 5 May 2021


Adverse events following immunisation with COVID-19 vaccines: Safety Report #5 – 3 April 2021


This page provides information on the number of adverse events following immunisation (AEFI) reports received for COVID-19 vaccines.

The national roll-out of COVID-19 vaccines commenced on 20 February 2021. The vaccine currently available in New Zealand is Pfizer-BioNTech (Comirnaty). All medicines can cause side effects, the known side effects for Comirnaty are listed in the data sheet and consumer medicine information.

Suspected AEFI to COVID-19 vaccines are reported to the Centre for Adverse Reactions Monitoring (CARM). The Ministry of Health (through Medsafe) contracts the collection of this information to CARM, based at the University of Otago in Dunedin. Medsafe is closely monitoring the AEFI reported from the use of the COVID-19 vaccine. Find out more about vaccine safety monitoring.

Adverse events following immunisation (AEFI) reported

The information below includes:

  • AEFI reports received and vaccine doses administered
  • AEFI reports by prioritised ethnicity and vaccine dose
  • AEFI reports by age band and vaccine dose
  • the top 10 most frequently reported AEFIs by vaccine dose.

AEFI reports received and vaccine doses administered, up to and including 3 April 2021


New AEFI reports since last update

(196 new non-serious and 7 new serious)


No safety signals (potential safety issues) have been identified


Total doses administered



Total AEFI reports that were non-serious


Total AEFI reports that were serious


Total AEFI reports that were received


Note that data clean-up has meant that case numbers have changed since the last update. There are now also no ‘dose unknown’ columns in the AEFI tables below due to this data clean-up.

There were 196 new non-serious and 7 new serious cases reported this week. Six of the serious reports were allergic reactions and were managed appropriately. The final serious report was for chest discomfort and fast heart rate.

Up to and including 3 April 2021, there have been 3 cases where the reporter indicated suspected anaphylaxis. CARM follow-up of these cases found that 1 case was anaphylaxis but not to the vaccine and 2 cases didn’t meet the Brighton Collaboration case definition for anaphylaxis.

AEFI reports received by prioritised ethnicity and vaccine dose, up to and including 3 April 2021

Ethnicitya Dose 1 Dose 2 Total
Māori 39 13 52
Pacific Peoples 27 13 40
Asian 107 37 144
European/Other 302 114 416
Unknown 6 5 11
Total 481 182 663


  1. The prioritised ethnicity classification system allocates each person to a single ethnic group, based on the ethnic groups they identify with. Where people identify with more than one group, they are assigned in this order of priority: Māori, Pacific Peoples, Asian, and European/Other. So, if a person identifies as being Māori and New Zealand European, the person is counted as Māori. See Ethnicity Data Protocols for further information.

AEFI reports received by age band and vaccine dose, up to and including 3 April 2021

Age Dose 1 Dose 2 Total
10 - 19 years 20 1 21
20 - 29 years 126 36 162
30 - 39 years 108 44 152
40 - 49 years 86 47 133
50 - 59 years 89 39 128
60 - 69 years 42 14 56
70 - 79 years 8 0 8
80+ years 2 0 2
Unknown 0 1 1
Total 481 182 663

Top 10 most frequently reported AEFIs, any dose, up to and including 3 April 2021

Reaction Number
Headache 175
Dizziness 169
Nausea 128
Injection site pain 91
Fever 52
Fu-like illness 39
Muscle pain 39
Syncopea 37
Musculoskeletal pain 34
Lethargy 29


  1. Syncope: fainting

Top 10 most frequently reported AEFIs, dose 1 only, up to and including 3 April 2021

Reaction Number
Dizziness 132
Headache 99
Nausea 85
Injection site pain 64
Syncopea 33
Fever 22
Numbness 20
Flu-like illness 18
Tachycardiab 18
Vomiting 18


  1. Syncope: fainting
  2. Tachycardia: rapid heart rate

Top 10 most frequently reported AEFIs, dose 2 only, up to and including 3 April 2021

Reaction Number
Headache 76
Nausea 43
Dizziness 37
Fever 30
Musculoskeletal pain 28
Injection site pain 27
Muscle pain 25
Flu-like illness 21
Joint pain 20
Injection site inflammation 13

Please note that one adverse event report, which represents one person, may report on more than one symptom. Reports are sent to CARM if the reporter suspects that the vaccine may have caused the event. This does not necessarily mean that the vaccine did cause the event.

The number of reports can be influenced by how many people are being vaccinated, media attention, the nature of the events (eg, how painful the vaccination was), and other factors which vary over time. Not everyone who has an adverse reaction reports it, and some people may report AEFIs after each vaccination. The information here shows the number of reports not the number of people who experienced an AEFI.

The information is limited by the information provided in the report and may change over time due to quality control procedures and/or receipt of additional information. Non-valid reports are not included in the data.

Medsafe and CARM thank everyone who has contributed to the monitoring of COVID-19 vaccines. Please continue to report any adverse events following immunisation.


Adverse event following immunisation (AEFI)
An AEFI is an untoward medical event which follows immunisation and does not necessarily have a causal relationship with the administration of the vaccine. The adverse event may be an unfavourable or unintended sign, abnormal laboratory finding, symptom or disease.
Serious adverse event following immunisation
An AEFI is considered serious if it:
  • is a medically important event or reaction
  • requires hospitalisation or prolongs an existing hospitalisation
  • causes persistent or significant disability or incapacity
  • is life threatening
  • causes a congenital anomaly/birth defect
  • results in death.
It is possible for different people to have experienced the same event but for the report to be serious for one person and non-serious for another person.
Safety signal
Information on a new or known adverse event that may be caused by the vaccine and requires further investigation. Safety signals can be detected from a wide range of sources such as CARM reports, clinical studies and scientific literature.
Valid report
There are only four requirements for a valid AEFI report:
  1. one patient identifier (eg, name, initials, gender, date of birth, age)
  2. suspect medicine(s)
  3. suspected reaction(s)
  4. reporter details.
These four requirements are the minimum requirements. However, including more information in the report helps Medsafe to investigate the reaction more quickly. Reporting is easiest online.

More information

See the data sheets and consumer medicine information for the expected reactions for approved COVID-19 vaccines.

COVID-19 Vaccine Safety Monitoring Process

View Ministry of Health COVID-19 vaccine data

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